In medical diagnostic test devices, biological fluids such as whole blood, plasma, serum, nasal secretions, sputum, saliva, urine, sweat, transdermal exudates, cerebrospinal fluids and the like may be analyzed for specific components and properties that are clinically important for monitoring and diagnosis. As is well understood in the medical community, lateral flow test strips can be used in medical and other applications to provide convenient and simple analysis of many important biological fluid samples. Microfluidic devices can also be used in the assaying of biological samples.